1. Field Of The Invention
This invention relates to the high speed transfer of cylindrical articles from a jumbled mass at a bulk inlet to a stream of articles aligned end-to-end and having uniform spacing. The articles are then transferred by a series of vacuum transfer drums to an assembly drum, where they are joined with other components.
In particular, the present apparatus, comprising a bowl feeder and a series of belt conveyors, is designed to sort relatively frail carbon rods and to present the carbon rods in an end-to-end uniformly spaced stream for incorporation into a smoking article, such as that described in commonly assigned copending U.S. application Ser. No. 315,822. These carbon rods are relatively small objects, about one-half inch long and one-eighth inch in diameter. Special consideration was given in designing the apparatus of the present invention so as to maintain the structural integrity of the carbon rods, which are strongest under axial compressive loads.
2. Prior Art
The use of bowl feeders to unsort a jumbled mass of articles is well known, and is described for example in Brackmann et al. U.S. Pat. No. 3,868,013 and Schmitz U.S. Pat. No. 4,369,875. Brackmann U.S. Pat. No. 3,868,013 describes the use of centrifugal forces created by rotation of the bowl to displace the articles into a groove along the periphery of the bowl. Schmitz U.S. Pat. No. 4,369,875 describes the use of a spiral sidewall disposed above a rotating mat, so that articles placed on the mat are guided by the sidewall into a continuous stream aligned end-to-end. The result of both of the above bowl feeders is to achieve a stream of articles aligned end-to-end at the exit of the bowl feeder. The present invention includes a centrifugal bowl feeder similar to that described in Brackmann et al. U.S. Pat. No. 3,868,013.
The use of a series of belt conveyors to transport cylindrically spaced-apart articles is also well known. Such conveyor systems are shown in Engel U.S. Pat. No. 3,323,633, Williams et al. U.S. Pat. No. 3,978,969 and Cristiani U.S. Pat. No. 4,296,660. A number of methods are used to achieve a grip on the article to be transported so as to permit its forward displacement along the belt conveyor. Engel U.S. Pat. No. 3,323,633, relies on frictional forces between the articles and the belt conveyor, created by the weight of the articles, to achieve a grip on the articles transported. Williams et al. U.S. Pat. No. 3,978,969, shows the use of opposing belts where some slippage between the article and the belts is desired and the use of a lugged belt where positive engagement between the belt and article is required. Cristiani U.S. Pat. No. 4,296,660 shows the use of a suction belt conveyor to maintain a desired relationship between articles carried on the belt surface.
Williams et al. U.S. Pat. No. 3,978,969 describes an arrangement of smooth and lugged belt conveyors that can be used to achieve acceleration and spacing of articles along the length of the belts. A disadvantage of this system, noted in that patent, is the inability of the system to achieve uniform spacing of the articles. Instead, a lugged timing wheel is provided specifically to regulate the spacing of the articles.
In view of the foregoing, it is an object of the present invention to provide a method and apparatus for sorting and transporting articles at uniform intervals without the use of a timing wheel and associated mechanisms.
It is another object of this invention to provide a method and apparatus for sorting and transporting articles at uniform intervals wherein uniform spacing is achieved by the arrangement and synchronization of the belt conveyor system components.
It is still another object of this invention to provide a high speed system for feeding cylindrical articles which is able to smooth out fluctuations in the stream of articles exiting a bowl feeder so that a continuous stream of uniformly spaced articles is provided at the transfer point of the feed system.
It is yet another object of this invention to provide a high speed transfer system which permits the sorting and transfer of small, fragile, cylindrical articles, with a minimum of breakage.
It is another object of this invention to provide a method and apparatus for assembling a stream of carbon rods into smoking article components at high speed.